Flexible touch screen panel and flexible display device with the same

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application based on pending application Ser. No. 13/888,574, filed May 7, 2013, which in turn claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 61/643,566, filed on May 7, 2012 and entitled “FLEXIBLE TOUCH SCREEN PANEL AND FLEXIBLE DISPLAY DEVICE WITH THE SAME,” both of which are incorporated herein by reference in its entirety.

This application claims the benefit of and priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2013-0012887, filed on Feb. 5, 2013, in the Korean Intellectual Property Office, and entitled: “FLEXIBLE TOUCH SCREEN PANEL AND FLEXIBLE DISPLAY DEVICE WITH THE SAME,” which is incorporated by reference herein in its entirety.

BACKGROUND

1. Field

Embodiments relate to a flexible touch screen panel and a flexible display device with the same.

2. Description of the Related Art

A touch screen panel is an input device that allows a user's instruction to be input by selecting an instruction content displayed on a screen of a display device or the like with a user's hand or object. The touch screen panel may be formed on a front face of the display device to convert a contact position into an electrical signal. The user's hand or object may directly contact the touch screen panel at the contact position. Accordingly, the instruction content selected at the contact position may be input as an input signal to the image display device. Since such a touch screen panel may be substituted for a separate input device connected to a display device, such as a keyboard or mouse, its application fields have been gradually extended.

SUMMARY

Embodiments are directed to a flexible touch screen panel, including a substrate having flexibility, sensing electrodes on at least one surface of the substrate, and implemented using an opaque conductive metal, and a polarizing plate on the substrate having the sensing electrodes formed thereon. The sensing electrodes may be implemented in a mesh shape having a plurality of openings.

The sensing electrodes may be implemented with first sensing electrodes arranged in a first direction and second sensing electrodes arranged in a second direction intersecting the first direction.

The first sensing electrodes may be configured with a plurality of first sensing cells arranged along the first direction and first connection patterns connecting the first sensing cells to each other, and the second sensing electrodes are configured with a plurality of second sensing cells arranged along the second direction and second connection patterns connecting the second sensing cells to each other.

The first sensing electrodes and the second sensing electrodes may be on the same surface of the substrate.

An insulation layer may be interposed in at least one intersection portion between the first and second sensing electrodes.

The first sensing electrodes and the second sensing electrodes may be respectively on different surfaces of the substrate.

The opaque metal may be at least one low-resistance metal selected from the group of Ag, Al, Cu, Cr, and Ni, or a nano-metal conductive layer.

The polarizing plate may be implemented with a film made of a poly vinyl alcohol having flexibility.

The polarizing plate may be implemented with a coating-type polarizing layer.

The coating-type polarizing layer may be formed with a thin crystal film polarizer.

The substrate may be implemented with one of a non-stretched polycarbonate and a cyclic polyolefin, as a low retardation film having a low retardation value.

At least one retardation film may be between the substrate and the polarizing plate.

The retardation film may be a quarter-wave plate or half-wave plate.

The substrate may be implemented with one of a polycarbonate film, an oriented poly propylene film, and a poly vinyl alcohol film, which have a retardation function.

The substrate may be a quarter-wave plate.

A half-wave plate may be between the substrate and the polarizing plate.

Embodiments are also directed to a flexible display device with a flexible touch screen panel, including a substrate having flexibility, sensing electrodes on at least one surface of the substrate, and implemented using an opaque conductive metal, a polarizing plate on the substrate having the sensing electrodes thereon, and the flexible display device attached beneath the substrate. The sensing electrodes may be implemented in a mesh shape having a plurality of openings.

The flexible display device may be implemented as an organic light emitting display device.

A window substrate may be attached to an upper surface of the polarizing plate.

The window substrate may be formed of at least one of polymethyl methacrylate, acryl, and polyester.

BRIEF DESCRIPTION OF THE DRAWINGS

Features will become apparent to those of skill in the art by describing in detail example embodiments with reference to the attached drawings in which:

<figref idref="DRAWINGS">FIG. 1</figref> is a plan view showing a touch screen panel according to an example embodiment.

<figref idref="DRAWINGS">FIGS. 2A and 2B</figref> are sectional views of the touch screen panel shown in <figref idref="DRAWINGS">FIG. 1</figref>.

<figref idref="DRAWINGS">FIGS. 3A and 3B</figref> are sectional views showing a touch screen panel and a flexible display device with the same according to an example embodiment.

<figref idref="DRAWINGS">FIGS. 4A and 4B</figref> are sectional views showing a touch screen panel and a flexible display device with the same according to another example embodiment.

<figref idref="DRAWINGS">FIG. 5</figref> is a sectional view showing a touch screen panel and a flexible display device with the same according to still another example embodiment.

<figref idref="DRAWINGS">FIGS. 6A and 6B</figref> are sectional views showing a touch screen panel and a flexible display device with the same according to still another example embodiment.

<figref idref="DRAWINGS">FIG. 7</figref> is a sectional view showing a touch screen panel and a flexible display device with the same according to still another example embodiment.

<figref idref="DRAWINGS">FIGS. 8A and 8B</figref> are sectional views showing a touch screen panel and a flexible display device with the same according to still another example embodiment.

DETAILED DESCRIPTION

Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings; however, they may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the example embodiments to those skilled in the art.

In the drawing figures, dimensions may be exaggerated for clarity of illustration. It will be understood that when an element is referred to as being “on” another element, it may be directly on the other element, or one or more intervening elements may also be present. It will also be understood that when an element is referred to as being “under” another element, it may be directly under, or one or more intervening elements may also be present. It will also be understood that when an element is referred to as being “between” two elements, it may be the only element between the two elements, or one or more intervening elements may also be present. Also, when an element is referred to as being “connected to” another element, it may be directly connected to the another element or be indirectly connected to the another element with one or more intervening elements interposed therebetween. Like reference numerals refer to like elements throughout.

<figref idref="DRAWINGS">FIG. 1</figref> is a plan view showing a touch screen panel according to an example embodiment. <figref idref="DRAWINGS">FIGS. 2A and 2B</figref> are sectional views of the touch screen panel shown in <figref idref="DRAWINGS">FIG. 1</figref>.

Referring to <figref idref="DRAWINGS">FIGS. 1 and 2</figref>, the touch screen panel according to the present example embodiment includes a substrate <b>10</b> having flexibility, first and second sensing electrodes <b>50</b> and <b>60</b> formed on at least one surface of the substrate <b>10</b>, and first and second position detecting lines <b>150</b> and <b>160</b> connecting the respective first and second sensing electrodes <b>50</b> and <b>60</b> to an external touch driving circuit (not shown) through a pad portion <b>200</b>.

As shown in <figref idref="DRAWINGS">FIG. 1</figref>, the first sensing electrode <b>50</b> is formed long in a first direction (e.g., an X-axis direction), and may be arranged in plural numbers along a second direction (e.g., a Y-axis direction) intersecting the first direction.

The second sensing electrode <b>60</b> is formed long in the second direction, and may be arranged in plural numbers along the first direction.

The sensing electrodes <b>50</b> and <b>60</b> according to the present example embodiment may be formed of a flexible opaque conductive material rather than a transparent conductive material (e.g., indium tin oxide (ITO)) in order to prevent an operation failure from being caused by a crack that occurs in the sensing electrode when the flexible touch screen panel is bent or folded. A low-resistance metal as an opaque metal, such as Ag, Al, Cu, Cr, or Ni, or a nano-metal conductive layer such as a silver nano-wire (AgNW) may be used as the conductive material of the sensing electrodes <b>50</b> and <b>60</b>. However, the present example embodiment is not limited thereto.

ITO may have insufficient flexibility when used for sensing electrodes and cracks may occur when the ITO is applied to the flexible touch screen panel. However, in the present example embodiment the opaque metal is used as the sensing electrodes, and the occurrence of cracks may be decreased as compared with the ITO, and thus the opaque metal may be easily applied to the flexible touch screen panel. Where the sensing electrodes <b>50</b> and <b>60</b> are formed of metal having a relatively lower resistance than the ITO, RC delay is also reduced.

Where the sensing electrodes <b>50</b> and <b>60</b> are formed of the opaque metal, the metal reflection gloss and surface reflectivity of the opaque metal may be increased so that a user can view the sensing electrodes <b>50</b> and <b>60</b>. Therefore, it may be difficult to implement a high-quality product. Thus, in the present example embodiment, a polarizing plate having flexibility is formed on the substrate <b>10</b> having the sensing electrodes <b>50</b> and <b>60</b> formed thereon, so that the metal reflection gloss may be removed and the surface reflectivity may be decreased, thereby reducing the visibility of the sensing electrodes.

In the present example embodiment, the substrate <b>10</b> having the sensing electrodes formed thereon is a low retardation film that is positioned below the polarizing plate and has a flexible material. The substrate <b>10</b> may be implemented with a non-stretched polycarbonate (PC) film, cyclic polyolefin (COP) film, etc.

In another implementation, the substrate <b>10</b> may perform the function of a retardation film provided in the polarizing plate. In the present example embodiment, the substrate <b>10</b> may be implemented with a PC, oriented poly propylene (OPP), or poly vinyl alcohol (PVA) film.

The structure of the present example embodiment as described above may be implemented as various example embodiments, and will be described in detail with reference to <figref idref="DRAWINGS">FIGS. 3 to 8</figref>.

In the present example embodiment, as shown in <figref idref="DRAWINGS">FIG. 1</figref>, the sensing electrodes <b>50</b> and <b>60</b> are formed in a mesh shape so that the opaque conductive material is used as the sensing electrode. Referring to <figref idref="DRAWINGS">FIG. 1</figref>, the first sensing electrode <b>50</b> may be configured with a first sensing cells <b>51</b> arranged in plural numbers in the first direction and a first connection pattern <b>52</b> electrically connecting the first sensing cells <b>51</b> to each other. The second sensing electrode <b>60</b> may be configured with a second sensing cell <b>61</b> arranged in plural numbers in the second direction and a second connection pattern <b>62</b> electrically connecting the second sensing cells <b>61</b> to each other.

A plurality of openings <b>70</b> are formed in the first sensing cell <b>51</b>, the second sensing cell <b>61</b>, the first connection pattern <b>52</b>, and the second connection pattern <b>62</b>, and accordingly, the mesh-shaped sensing electrode may be implemented.

In the present example embodiment, the first and second sensing cells <b>51</b> and <b>61</b> may have a rhombic shape, but the shape of the sensing cell according to the present example embodiment is not limited thereto.

A display device in which a plurality of pixels are regularly arranged to display an image is disposed beneath the substrate <b>10</b> having the sensing cells formed thereon. In a case where the shape and arrangement of the sensing cells have regularity, a Moiré phenomenon may occur due to interference between the pixels in the display device, and therefore, the display quality of the display device may be degraded. Thus, the frames of the sensing cells <b>51</b> and <b>61</b> may be implemented in the shape of a random curve.

In the present example embodiment, for convenience of illustration, a case where the sensing cells <b>51</b> and <b>61</b> are implemented in the same rhombic shape as shown in <figref idref="DRAWINGS">FIG. 1</figref> will be described as an example.

The first position detecting line <b>150</b> is connected to one end of the first sensing electrode <b>50</b>, and the second position detecting line <b>160</b> is connected to one end of the second sensing electrode <b>60</b>. The first and second position detecting lines <b>150</b> and <b>160</b> may transmit signals detected from the respective sensing electrodes <b>50</b> and <b>60</b> to the touch driving circuit (not shown) through the pad portion <b>200</b>. Thus, the touch driving circuit receiving the signals transmitted from the first and second position detecting lines <b>150</b> and <b>160</b> may detect a user's touch position.

In the present example embodiment, the first position detecting line <b>150</b> may be formed of the same material as the first sensing electrode <b>50</b> connected thereto, and the second position detecting line <b>160</b> may be formed of the same material as the second sensing electrode <b>60</b> connected thereto. Thus, the position detecting line <b>150</b> or <b>160</b> may be formed with the sensing electrode <b>50</b> or <b>60</b> through the same process, thereby further simplifying the process.

In the present example embodiment, the first and second sensing electrodes <b>50</b> and <b>60</b> may be formed together on the same surface of the substrate, or may be formed on both surfaces of the substrate <b>10</b>, respectively.

First, referring to <figref idref="DRAWINGS">FIG. 2A</figref>, there is shown a structure in which the first and second sensing electrodes <b>50</b> and <b>60</b> are formed together on the same surface of the substrate <b>10</b>. In the present example embodiment, the portion at which the first and second sensing electrodes <b>50</b> and <b>60</b> intersect each other is insulated, and an insulation layer <b>41</b> may be interposed in the intersection portion between the first and second sensing electrodes <b>50</b> and <b>60</b>.

The first and second sensing electrodes <b>50</b> and <b>60</b> intersect each other between the first and second connection patterns <b>52</b> and <b>62</b>. Therefore, as shown in the enlarged section of <figref idref="DRAWINGS">FIG. 2A</figref>, the insulation layer <b>41</b> may exist between the first and second connection patterns <b>52</b> and <b>62</b>. In the present example embodiment, the insulation layer <b>41</b> may be partially formed at the intersection portion of the first and second sensing electrodes <b>50</b> and <b>60</b>.

Next, referring to <figref idref="DRAWINGS">FIG. 2B</figref>, there is shown a structure in which the first and second sensing electrodes <b>50</b> and <b>60</b> are formed on both the surfaces of the substrate <b>10</b>, respectively. As shown in <figref idref="DRAWINGS">FIG. 2B</figref>, the substrate <b>10</b> performs the function of an insulation layer. Therefore, the first sensing cells <b>51</b> and the first connection patterns <b>52</b>, constituting the first sensing electrode <b>50</b>, may be formed on a first surface of the substrate <b>10</b>, and the second sensing cells <b>61</b> and the second connection patterns <b>62</b>, constituting the second sensing electrode <b>60</b>, may be formed on a second surface of the substrate <b>10</b>. In the present example embodiment, a separate insulation layer (as shown in <figref idref="DRAWINGS">FIG. 2A</figref>) may be omitted to simplify the process.

<figref idref="DRAWINGS">FIGS. 3 to 8</figref> are sectional views showing touch screen panels to which the structure of the touch screen panel described with reference to <figref idref="DRAWINGS">FIGS. 1 and 2</figref> and flexible display devices with the touch screen panels according to various example embodiments may be applied. Hereinafter, a stacked structure of an example embodiment corresponding to each figure will be described in detail.

First, in the example embodiment shown in <figref idref="DRAWINGS">FIG. 3A</figref>, like the example embodiment of <figref idref="DRAWINGS">FIG. 2B</figref>, first sensing cells <b>51</b> and first connection patterns <b>52</b>, constituting first sensing electrodes <b>50</b>, and first position detecting lines <b>150</b> connected to the first sensing electrodes <b>50</b> are formed on a first surface of a substrate <b>10</b><i>a</i>, and second sensing cells <b>61</b> and second connection patterns <b>62</b>, constituting second sensing electrodes <b>60</b>, and second position detecting lines <b>160</b> connected to the second sensing electrodes <b>60</b> are formed on a second surface of the substrate <b>10</b><i>a. </i>

However, for convenience of illustration, only the first sensing cells <b>51</b> and the first position detecting lines <b>150</b>, formed on the first surface of the substrate <b>10</b><i>a </i>and only the second sensing cells <b>61</b> and the second position detecting lines <b>160</b>, formed on the second surface of the substrate <b>10</b><i>a </i>are shown in <figref idref="DRAWINGS">FIG. 3A</figref>.

A polarizing plate <b>20</b> performing a polarizing function, a window substrate <b>40</b> attached to the top of the polarizing plate <b>20</b>, and a retardation film <b>10</b><i>b </i>attached to the bottom of the polarizing plate <b>20</b> are provided above the substrate <b>10</b><i>a </i>having the sensing electrodes formed thereon. A flexible display device <b>100</b> is provided below the substrate <b>10</b><i>a. </i>

In the present example embodiment, the components are attached to each other by a transparent adhesive layer <b>30</b>. In <figref idref="DRAWINGS">FIG. 3A</figref>, it has been illustrated that the substrate <b>10</b><i>a </i>having the sensing electrodes formed thereon is separated. However, this is for the purpose that the position of the sensing cell or the like is clearly illustrated. Thus, the substrate <b>10</b><i>a </i>is attached to the components by the transparent adhesive layers <b>30</b> respectively formed on the top and bottom of the substrate <b>10</b><i>a. </i>

The display device <b>100</b> is a display device having flexibility, and may be implemented as an organic light emitting display device. For example, unlike a liquid crystal display device, the organic light emitting display device as a self-luminescent device does not require a backlight unit. A substrate is formed of, e.g., polymethyl methacrylate (PMMA), acryl, polyester (PET) or the like, which has flexibility. Thus, the organic light emitting display device can have flexibility.

The transparent adhesive layer <b>30</b> is a transparent adhesive material having high light transmittance. The transparent adhesive layer <b>30</b> may be made of super view resin (SVR) or optically clear adhesive (OCA).

The polarizing plate <b>20</b> has flexibility.

A general polarizing plate may be implemented in a structure in which a polarizer is interposed between upper and lower support layers. The polarizer performs a function of controlling the amount of transmitted light according to the polarized degree of incident light. The polarizer may be implemented with a film made of a PVA material. For example, the polarizer implements polarization by stretching a PVA film having iodine absorbed therein with strong tension. The support layers respectively provided on the upper and lower surfaces of the polarizer may be implemented with a film made of a triacetyl cellulose (TAC) material for protecting and supporting the PVA film. However, in the general polarizing plate having the stacked structure, the polarizer has a thickness of, e.g., about 20 μm, and each of the upper and lower support layers has a thickness of, e.g., about 80 μm. Therefore, the polarizing plate entirely has a great thickness of, e.g., about 180 μm.

TAC (a material of the general support layer) has high elasticity. Therefore, if the polarizing plate having the support layers is attached to the flexible touch screen panel, it may not be possible to secure the bending characteristic of the flexible touch screen panel. Accordingly, in the present example embodiment, the polarizing plate <b>20</b> is implemented by removing at least one support layer (relative to the general polarizing plate) and forming the support layer using a material with flexibility, or is implemented by forming a coating-type polarizing layer on the flexible support layer.

In the present example embodiment, the coating-type polarizing layer may be formed in various structures and manners. For example, the coating-type polarizing layer may be formed with a thin crystal film polarizer.

The retardation film <b>10</b><i>b </i>is attached beneath the polarizing plate <b>20</b>. The retardation film <b>10</b><i>b </i>performs a function of providing a temporal phase shift (retardation) to light polarized by the polarizing plate <b>20</b> so that incident light is converted into circularly polarized light or almost circularly polarized light through left or right circular polarization.

In the example embodiment of <figref idref="DRAWINGS">FIG. 3A</figref>, the retardation film <b>10</b><i>b </i>is a quarter-wave plate (QWP) having a retardation function. For example, the retardation film <b>10</b><i>b </i>may be implemented as a PC, OPP, or PVA film.

In the present example embodiment, the retardation film may be implemented in the stacked structure of a plurality of retardation films having different retardation values in order to secure the optimal black characteristic for light transmitted through the polarizing plate <b>20</b>.

Thus, when comparing the example embodiment of <figref idref="DRAWINGS">FIG. 3B</figref> with the example embodiment of <figref idref="DRAWINGS">FIG. 3A</figref>, the example embodiment of <figref idref="DRAWINGS">FIG. 3B</figref> has a structure in which a retardation film <b>10</b><i>c </i>as a half-wave plate (HWP) is further provided on the retardation film <b>10</b><i>b </i>as the QWP. In the example embodiment of <figref idref="DRAWINGS">FIG. 3B</figref>, the structure is identical to that of <figref idref="DRAWINGS">FIG. 3A</figref>, except that the HWP is further provided, and therefore details thereof will not be repeated.

In the example embodiment of <figref idref="DRAWINGS">FIGS. 3A and 3B</figref>, one or more retardation films <b>10</b><i>b </i>and <b>10</b><i>c </i>are provided to the lower surface of the polarizing plate <b>20</b>. Therefore, the substrate <b>10</b><i>a </i>on which the sensing cells <b>51</b> and <b>61</b>, etc., are formed may be implemented with a non-stretched polycarbonate (PC) film, cyclic polyolefin (COP) film, etc., as a low retardation film having flexibility and very low retardation value (about 20 nm or less).

Since the display device <b>20</b> and the touch screen panel have flexibility, the window substrate <b>40</b> attached to the upper surface of the polarizing plate <b>10</b> for the purpose of strength improvement may be implemented using a material with flexibility. Therefore, in the present example embodiment, the window substrate <b>40</b> may be made of PMMA, acryl, PET, etc., and the thickness of the window substrate <b>40</b> may be about 0.7 mm.

Next, in the example embodiments shown in <figref idref="DRAWINGS">FIGS. 4A and 4B</figref>, like the example embodiment of <figref idref="DRAWINGS">FIG. 2A</figref>, the sensing electrodes <b>50</b> and <b>60</b> are formed on the same surface of the substrate <b>10</b><i>a</i>. The stacked structure of the other components is identical to that in the example embodiment of <figref idref="DRAWINGS">FIG. 3A</figref>, and therefore details thereof will not be repeated.

Thus, the example embodiment of <figref idref="DRAWINGS">FIG. 4A</figref> has a structure in which the first and second sensing cells <b>51</b> and <b>61</b> constituting the respective first and second sensing electrodes <b>50</b> and <b>60</b>, and the first and second position detecting lines <b>150</b> and <b>160</b> connected to the respective first and second sensing electrodes <b>50</b> and <b>60</b> are formed on a second surface that is an upper surface of the substrate <b>10</b><i>a. </i>

The example embodiment of <figref idref="DRAWINGS">FIG. 4B</figref> has a structure in which the first and second sensing cells <b>51</b> and <b>61</b> constituting the respective first and second sensing electrodes <b>50</b> and <b>60</b>, and the first and second position detecting lines <b>150</b> and <b>160</b> connected to the respective first and second sensing electrodes <b>50</b> and <b>60</b> are formed on a first surface that is a lower surface of the substrate <b>10</b><i>a. </i>

Although it has been illustrated in the example embodiment of <figref idref="DRAWINGS">FIGS. 4A and 4B</figref> that only one retardation film <b>10</b><i>b </i>is provided, the retardation film <b>10</b><i>b </i>may be implemented in the stacked structure of a plurality of retardation films having different retardation values as shown in <figref idref="DRAWINGS">FIG. 3B</figref>.

Next, when comparing the example embodiment shown in <figref idref="DRAWINGS">FIG. 5</figref> with the example embodiment of <figref idref="DRAWINGS">FIG. 3A</figref>, the example embodiment of <figref idref="DRAWINGS">FIG. 5</figref> is different the example embodiment of <figref idref="DRAWINGS">FIG. 3A</figref> in that the substrate <b>10</b><i>b </i>having sensing electrodes formed thereon is implemented with a retardation film <b>10</b><i>b </i>disposed below the polarizing plate <b>20</b>, rather than the low retardation film having very low retardation value (about 20 nm or less).

Thus, the example embodiment of <figref idref="DRAWINGS">FIG. 5</figref> has a structure in which the first sensing cells <b>51</b> and the first connection patterns <b>52</b>, constituting the first sensing electrodes <b>50</b>, and the first position detecting lines <b>150</b> connected to the first sensing electrodes <b>50</b> are formed on a first surface of the retardation film <b>10</b><i>b</i>, and the second censing cells <b>61</b> and the second connection patterns <b>62</b>, constituting the second sensing electrodes <b>60</b>, and the second position detecting lines <b>160</b> connected to the second sensing electrodes <b>60</b> are formed on a second surface of the retardation film <b>10</b><i>b. </i>

Thus, in the example embodiment of <figref idref="DRAWINGS">FIG. 5</figref>, it is possible to remove the substrate provided in the example embodiment of <figref idref="DRAWINGS">FIG. 3A</figref>, i.e., the substrate <b>10</b><i>a </i>implemented with the low retardation film having very low retardation value (about 20 nm or less), to thereby implement an ultra-thin flexible touch screen panel.

In the present example embodiment, the retardation film <b>10</b><i>b </i>as the substrate on which the sensing cells <b>51</b> and <b>61</b>, etc., are formed may be implemented with a PC, OPP or PVA film having a retardation function.

Among the components constituting the example embodiment of <figref idref="DRAWINGS">FIG. 5</figref>, components identical to those in the example embodiment of <figref idref="DRAWINGS">FIG. 3</figref> are designated by like reference numerals, and details thereof will not be repeated.

In the example embodiments of <figref idref="DRAWINGS">FIGS. 6A and 6B</figref>, like the example embodiment of <figref idref="DRAWINGS">FIG. 5</figref>, the sensing electrodes <b>50</b> and <b>60</b> are formed on the same surface of a substrate <b>10</b><i>b </i>as a retardation film. The stacked structure of the other components is identical to that in the example embodiment of <figref idref="DRAWINGS">FIG. 5</figref>, and therefore details thereof will not be repeated.

Thus, the example embodiment of <figref idref="DRAWINGS">FIG. 6A</figref> has a structure in which the first and second sensing cells <b>51</b> and <b>61</b> constituting the respective first and second sensing electrodes <b>50</b> and <b>60</b>, and the first and second position detecting lines <b>150</b> and <b>160</b> connected to the respective first and second sensing electrodes <b>50</b> and <b>60</b> are formed on a second surface that is an upper surface of the substrate <b>10</b><i>b. </i>

The example embodiment of <figref idref="DRAWINGS">FIG. 6B</figref> has a structure in which the first and second sensing cells <b>51</b> and <b>61</b> constituting the respective first and second sensing electrodes <b>50</b> and <b>60</b>, and the first and second position detecting lines <b>150</b> and <b>160</b> connected to the respective first and second sensing electrodes <b>50</b> and <b>60</b> are formed on a first surface that is a lower surface of the substrate <b>10</b><i>b. </i>

Next, when comparing the example embodiment shown in <figref idref="DRAWINGS">FIG. 7</figref> with the example embodiment of <figref idref="DRAWINGS">FIG. 5</figref>, the example embodiment of <figref idref="DRAWINGS">FIG. 7</figref> is different the example embodiment of <figref idref="DRAWINGS">FIG. 5</figref> in that a second retardation film <b>10</b><i>c </i>having a retardation value different from that of a first retardation film <b>10</b><i>b </i>having sensing electrodes formed thereon is further provided between the first retardation film <b>10</b><i>b </i>and the polarizing plate <b>20</b>.

Thus, if the first retardation film <b>10</b><i>b </i>is a QWP having a retardation function as an example, the second retardation film <b>10</b><i>c </i>as an HWP is further provided between the first retardation film <b>10</b> and the polarizing plate <b>20</b> in order to secure the optimal black characteristic for light transmitted through the polarizing plate <b>20</b>.

Among the components constituting the example embodiment of <figref idref="DRAWINGS">FIG. 7</figref>, components identical to those in the example embodiment of <figref idref="DRAWINGS">FIG. 5</figref> are designated by like reference numerals, and therefore details thereof will not be repeated.

In the example embodiments of <figref idref="DRAWINGS">FIGS. 8A and 8B</figref>, like the example embodiment of <figref idref="DRAWINGS">FIG. 7</figref>, the sensing electrodes <b>50</b> and <b>60</b> are formed on the same surface of the substrate <b>10</b><i>b </i>as the first retardation film. The stacked structure of the other components is identical to that in the example embodiment of <figref idref="DRAWINGS">FIG. 7</figref>, and therefore details thereof will not be repeated.

Thus, the example embodiment of <figref idref="DRAWINGS">FIG. 8A</figref> has a structure in which the first and second sensing cells <b>51</b> and <b>61</b> constituting the respective first and second sensing electrodes <b>50</b> and <b>60</b>, and the first and second position detecting lines <b>150</b> and <b>160</b> connected to the respective first and second sensing electrodes <b>50</b> and <b>60</b> are formed on a second surface that is an upper surface of the first retardation film <b>10</b><i>b. </i>

The example embodiment of <figref idref="DRAWINGS">FIG. 8B</figref> has a structure in which the first and second sensing cells <b>51</b> and <b>61</b> constituting the respective first and second sensing electrodes <b>50</b> and <b>60</b>, and the first and second position detecting lines <b>150</b> and <b>160</b> connected to the respective first and second sensing electrodes <b>50</b> and <b>60</b> are formed on a first surface that is a lower surface of the first retardation film <b>10</b><i>b. </i>

By way of summation and review, touch screen panels may be divided into a resistive overlay touch screen panel, a photosensitive touch screen panel, a capacitive touch screen panel, and the like. Among these touch screen panels, the capacitive touch screen panel converts a contact position into an electrical signal by sensing a change in capacitance formed between a conductive sensing electrode and an adjacent sensing electrode or ground electrode when a user's hand or object comes in contact with the touch screen panel. Generally, such a touch screen panel is frequently commercialized by being attached to an outer face of a flat panel display such as a liquid crystal display or organic light emitting display. Therefore, the touch screen panel requires characteristics of high transparency and thin thickness. A flexible display device has recently been developed, and a touch screen panel attached on the flexible display device also requires flexibility.

In a general touch screen panel, the sensing electrodes may be implemented using a transparent conductive material such as indium tin oxide (ITO). However, when the flexible touch screen panel is bent or folded, cracks may occur in the sensing electrodes, and therefore, an operation failure may be caused. In a general touch screen panel, a thin-film growth process, a pattern formation process, and the like may be used for forming the sensing electrodes and the like, and therefore, characteristics such as high thermal resistance and chemical resistance may be required. Accordingly, the sensing electrodes and the like may be formed on a glass substrate in view of the process characteristics. However, the glass substrate should have a thickness with a certain value or more so as to be carried during processes. Therefore, the glass substrate may not be sufficiently thin or flexible.

As described above, embodiments may provide a flexible touch screen panel in which sensing electrodes as touch sensors are formed in the shape of a flexible conductive mesh on at least one surface of a substrate having flexibility. Thus, it may be possible to secure the flexibility of the flexible touch screen panel and to decrease the thickness of the flexible touch screen panel. Embodiments may also provide a flexible touch screen panel in which a polarizing plate having flexibility is formed on the substrate having the sensing electrodes formed thereon. Thus, it may be possible to reduce visibility of the sensing electrodes. Embodiments may also provide a flexible display device with the flexible touch screen panel.

As described above, according to embodiments, sensing electrodes as touch sensors may be formed in the shape of a flexible conductive mesh on at least one surface of a substrate having flexibility. Thus, it may be possible to secure the flexibility of the flexible touch screen panel and to decrease the thickness of the flexible touch screen panel. Further, a polarizing plate having flexibility may be formed on the substrate having the sensing electrodes formed thereon. Thus, it may be possible to reduce visibility of the sensing electrodes.

Example embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. In some instances, as would be apparent to one of ordinary skill in the art as of the filing of the present application, features, characteristics, and/or elements described in connection with a particular embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise specifically indicated. Accordingly, it will be understood by those of skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.